Fas and Fas Ligand (FasL) belong to the TNF superfamily and are type I and type II transmembrane proteins, respectively. Binding of FasL to Fas triggers apoptosis in Fas-bearing cells. The mechanism of apoptosis involves recruitment of pro-caspase 8 through an adaptor molecule called FADD followed by processing of the pro-enzyme to active forms. These active caspases then cleave various cellular substrates leading to the eventual cell death. sFasR is capable of inhibiting FasL-induced apoptosis by acting as a decoy receptor that serves as a sink for FasL.
Source
Escherichia coli.
Molecular Weight
Approximately 17.6 kDa, a single non-glycosylated polypeptide chain containing 157 amino acids.
Biological Activity
Fully biologically active when compared to standard. The ED50 as determined by its ability to inhibit the cytotoxicity of Jurkat cells is between 10-15 ug/ml in the presence of 2 ng/ml of rHuFas Ligand.
Appearance
Sterile filtered white lyophilized (freeze-dried) powder.
Formulation
Lyophilized from a 0.2 um filtered concentrated solution in PBS, pH 7.4.
Endotoxin
Less than 1 EU/ug of rHusFasR/TNFRSF6 as determined by LAL method.
Reconstitution
We recommend that this vial be briefly centrifuged prior to opening to bring the contents to the bottom. Reconstitute in sterile distilled water or aqueous buffer containing 0.1 % BSA to a concentration of 0.1-1.0 mg/mL. Stock solutions should be apportioned into working aliquots and stored at ≤ -20 °C. Further dilutions should be made in appropriate buffered solutions.
Stability and Storage
Use a manual defrost freezer and avoid repeated freeze-thaw cycles.- 12 months from date of receipt, -20 to -70 °C as supplied.- 1 month, 2 to 8 °C under sterile conditions after reconstitution.- 3 months, -20 to -70 °C under sterile conditions after reconstitution.
